I

ANNO 2 Numero 3
Stefan Bogdanov [1], Verena Kilchenmann, Anton Imdorf, Peter Galliman
Beeswax: a natural product at risk

[1] Agroscope Liebefeld-Posieux, Swiss Bee Research Centre, Liebefeld - Bern (CH)

Corresponding author: stefan.bogdanov@alp.admin.ch

This article deals with the main quality issues of Apis mellifera beeswax: production by bees and processing by beekeepers and manufacturers, overall chemical composition, as well as sensory and physicochemical characteristics. Information on beeswax economy and on beeswax uses is given. The main quality issues today are adulteration and contamination. Contamination from the environment being relatively small, the main contaminants are synthetic and persistent acaricides used in beekeeping. Several studied were carried out by the Swiss Bee Research Centre since 1991. The contamination levels of bromopropylate (Folbex VA), coumaphos (Perizin), fluvalinate (Apistan), and thymol (Apilife VAR) in beeswax and honey were studied after field trials. All samples were analysed by chromatography with ECD detection. After one normal acaricide treatment, beeswax was contaminated by all the active ingredients, the residue level in honeycombs being 5 to 10 times lower than that of broodcombs. The residues in the honey were all below the Swiss MRL (Maximum Residue Limit). Residue levels of thymol were investigated during storage: the study of the evaporation of thymol in different storage conditions showed that it evaporated very rapidly if foundation were stored on frames with free access of air or placed in a beehive during the honey flow. The behaviour of four acaricides - bromopropylate, coumaphos, fluvalinate and flumethrin (Bayarol) – and of thymol and p-dichlorobenzene during the recycling of old combs into new beeswax was examined in a laboratory experiment under different boiling temperatures. The acaricide concentration in the new wax was on average 1.7 times higher than in old combs under all conditions, with the exception of p-dichlorobenzene, the concentration of which remained unaltered. The results of a long-term monitoring of Swiss commercial beeswax are shown. All commercial samples contain bromopropylate, coumaphos, fluvalinate, thymol and p-dichlorobenzene in varying amounts. The investigations show that the acaricide concentration in wax increases with increasing number of applications, but decreases very slow after acaricide use has ceased. Measures for prevention of contamination are discussed.